Quite often in telephone conversations the parties do not speak at the same volume, nor place the handset equally distant from their mouth, nor experience the same level of ambient noise, etc. These different conditions manifest themselves in the voice call where one party is perceived at a lower volume level than the other. Typically the recipient of the lower volume subconsciously raises his voice, which results in the lower-volume caller compensating by lowering her voice even further. It is quite frustrating to work through these adjustments by trial and error until a stable conversation is realized, and even then, the results are often far from optimal. Although some phones have a built-in volume control, many do not, and phone calls at either too high or too low volume due to different speaker loudness or poorly functioning telephone equipment can be very annoying.
Therefore, it is a drawback of the prior art that the audio signal strength (i.e., volume) of each both call paths cannot be automatically adjusted to a pre-defined “normal” level.